The present invention generally relates to medical devices and methods. More particularly, the present invention relates to devices and methods for diagnosing and/or treating spinal pain.
Back pain takes an enormous toll on the health and productivity of people around the world. According to the American Academy of Orthopedic Surgeons, approximately 80 percent of Americans will experience back pain at some time in their life. In just the year 2000, approximately 26 million visits were made to physicians' offices due to back problems in the United States.
In at least some instances, surgical prostheses can be used to relieve back pain. Many of these prosthesis relieve pressure and/or irritation of nerve roots near the vertebral joints. Such treatments can be effective when the source of pain can be localized to a specific inter-vertebral joint and/or disc.
Unfortunately, back pain can be difficult and invasive to accurately diagnose in an effective manner that determines where the pain originates. Axial pain can be caused by disc failure that results in compression of nerves. “Discogenic pain,” for example, is a type of spinal pain originating in one or more intervertebral discs (soft tissue structures between vertebrae of the spine). The physical examination and complaints of the patient may merely provide general clues as to the cause and general location of the pain.
One approach to determine the source of back pain, can be to perform provocative discography. This procedure can include penetrating the patient's skin and injecting a contrast agent into the disc. The disc can be imaged with fluoroscopy, radiographs, CT scans, or the like with the aid of the contrast agent. Alternatively, a new technique referred to as Functional Anesthetic Discography (FAD) has been developed wherein the disc can be further evaluated with functional tests in which the patient assumes a painful position and the disc is injected with an analgesic or similar substance to determine if the pain diminishes in response to the injection into the disc.
Placement of the spinal needles to test the discs may require skill and time on the clinician's part and can be painful to the patient, even when good technique is used. In some instances, provocative discography may use two needles for each disc. As the patient may have more that one disc that may be a possible source of back pain, each of these suspected discs may be tested to determine which, if any, of the discs is the source of the patient's pain. The testing of multiple discs, for example three discs, can be time consuming and may result in multiple injections for the patient, each of which can be painful. Invasive tearing of tissues, for example associated with conventional needles and the like, may cause tissue trauma and delay recovery in some patients. In addition, some catheters and needles may potentially rub against nerve roots, such that the patient experiences pain, and in some instances may obscure test results.
For these reasons, it would be desirable to provide apparatus and methods for facilitating the diagnosis and treatment of spinal pain. It would be particularly desirable if such methods and apparatus were less invasive and painful than current methods and apparatus, and assured reliable determination of the source of patient pain, ideally while allowing the clinician flexibility with respect to which approach is used in a manner that accommodates patient variability.
Related devices and methods are disclosed in U.S. Patent Publication No. 2005/0234425 describes a Functional Anesthetic Discography (FAD) catheter, the full disclosure of which is incorporated herein by reference. Additional art that may be relevant includes U.S. application Ser. Nos. 11/021,786 and 60/826,472, the full disclosures of which are incorporated herein by reference, and International Publication No. WO 2005/102440.